Hot Carcass Research Articles

Exposure to Prenatal Tributyrin Improved Pre-Weaning Growth Performance and Reduced Fat Deposition in the Muscle of Market Age Pigs

Organic acids, including short chain fatty acids, medium chain fatty acids, and tricarboxylic acid, are used as alternatives to antibiotics for the purpose of growth promotion in livestock species. Butyric acid has been used extensively for its various functions in intestinal health and barrier function, as well as its actions as a histone deacetylase inhibitor. Many of the issues related to using butyric acid as a feed supplement are overcome by utilizing tributyrin (TB), a butyrate prodrug. Dietary supplementation of TB to sows during gestation was able to improve pre-weaning litter performance. Sows (n=52, 42 gestational days) were randomly assigned to either a control diet or control diet supplemented with 2% TB. All diets were made isocaloric with the addition of oil and wheat flour. Dietary treatments continued until 112 days of gestation. After farrowing, piglet growth performance was monitored. Once offspring reached 6 months of age, 30 gilts from the most median performing litters were identified for tissue collection and evaluation of meat characteristics. Sows that received tributyrin during gestation tended to have higher total litter weights at birth (P value < 0.1), however, average individual birthweights were not statistically different between control and TB litters. TB piglets tended to be heavier at weaning (P value < 0.1). Pre-weaning average daily gains were higher in piglets exposed to prenatal TB (P value < 0.01). Live weights and hot carcass weights did not differ significantly in gilts at market age. There was, however, a trend of increased dressing percentage from TB treated offspring, accompanied by significantly reduced back fat at the 10th rib (P value < 0.1 and P value < 0.05 respectively). This data suggests that TB supplementation results in both temporary and permanent improvements to growth and development. This study provides further evidence that prenatal TB can have long term effects on muscle growth and meat quality. Further studies are needed to ultimately determine whether prenatal or postnatal supplementation is ideal for improving long-term growth performance. USDA Grant Funded. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Prediction of Live Weight and Carcass Characteristics from Linear Body Measurements of Yearling Male Local Sheep

Measurements of the body structure in sheep are worthy of judging the quantitative features of meat and useful in developing appropriate selection requirements. The current study was aimed to predict live weight and hot carcass weight from linear body measurements of yearling male local sheep. 84 days feeding period fortnightly taken data on 24 local sheep for body weight, body length, heart girth, wither height, sub-sternal height, tail length, tail width, scrotal circumference, and scrotal length were analyzed to study the relationship between linear body measurements and body weight. At the end of the trial all sheep were slaughtered to measure the relationship between body measurements, and hot carcass weight. Microsoft Excel 2010 was used for data analysis. The relationships between the various body measurements were calculated using pearson's correlation coefficient. The backward stepwise multiple regression procedure was used for the determination of the most suitable model for the prediction of the live weight and hot carcass weight. Hot carcass weight was highly correlated (P<0.01) with body weight and scrotal circumference. Besides, it was significantly (P<0.05) correlated with tail width. Body weight was significantly (P<0.05) correlated with all body measurements except tail length and scrotal length. It is concluded that the body weight of the local sheep can be predicted with heart girth, sub-sternal height and tail width; the equation is LW= -97.2 + 0.36HG + 2.1SBSH + 0.57TW with a better coefficient of determination; R2 = 0.55 and the hot carcass weight can be predicted with sub-sternal height and tail width; the equation is HCW= -75.66 + 1.75SBSH + 0.85TW with a coefficient of determination; R2 = 0.33. But, hot carcass can be predicted with body weight, the equation is HCW= -9.39+0.85BWT when weighing scales are affordable with a better coefficient of determination; R2= 0.557.

Effects of Zilpaterol Hydrochloride with a Combination of Vitamin D3 on Feedlot Lambs: Growth Performance, Dietary Energetics, Carcass Traits, and Meat Quality.

This study evaluated the impact of supplementing ZH in combination with D3 on the growth performance, energy efficiency, carcass traits, and meat quality of feedlot lambs. Thirty-two Dorper × Katahdin cross lambs (37.3 ± 5.72 kg) were utilized in a 29 d experiment in a completely randomized block design with a 2 × 2 factorial structure consisting of two levels of ZH for 26 d (0 and 0.20 mg/kg PV-1) and two levels of D3 for 7 d (0 and 1.5 × 106 IU/d-1). ZH improved (p ≤ 0.05) the average daily gain (ADG) and feed efficiency by 9.9% and 17.8%, respectively, as well as hot carcass weight (HCW) and dressing carcass by 4.3% and 2.6%, respectively. (p ≤ 0.03). However, ZH increased (p < 0.01) muscle pH and Warner-Bratzler shear force (WBSF) (2.5 and 23.0%, respectively). D3 supplementation negatively affected (p ≤ 0.02) dry matter intake (DMI) (last 7 d) and ADG by 15.7% and 18.1%. On the other hand, D3 improved the pH of the longissimus thoracis muscle by 1.7% (p = 0.03) without affecting WBSF. When D3 was supplemented in combination with ZH, it was observed that meat quality was improved by reducing muscle pH compared to lambs treated only with ZH. However, D3 did not improve the meat tenderness negatively affected by ZH supplementation.

The importance of developmental programming in the beef industry

The beef industry relies on multiple focused segments (e.g., cow-calf, stocker/feeder, and meat packing) to supply the world with beef. Thus, the potential impact of developmental programming on the beef industry needs to be evaluated with regards to the different production traits that drive profitability within each segment. For example, when nutrient restriction of dams occurred early in gestation embryo survival was decreased and the ovarian reserve of heifer progeny was negatively affected. Restriction during mid- to late gestation negatively impacted first service conception rates and pregnancy success of daughters. Even non-nutrient stress has been reported to impact transgenerational embryo development through the male progeny. Primary and secondary muscle fibers form during months two to eight (Days 60–240) of gestation. Therefore, external stimuli (nutrition or environmental) during this window have the potential to decrease the postnatal number of muscle fibers; which has an irreversible impact on animal growth and performance. Nutrient restriction during the last third of gestation resulted in decreased weaning weights, and in some instances decreased dry mater intake, hot carcass weight, and marbling scores. Protein supplementation during late gestation; however, increased weaning weight and ADG to weaning, but progeny of dams restricted in protein in late gestation had greater ribeye area. The importance of developmental programming is recognized; however, its precise application depends on comprehension of its integrated effects across the multiple-focused segments of the beef industry.

Three-dimensional imaging to estimate in vivo body and carcass chemical composition of growing beef-on-dairy crossbred bulls

The dynamics of cattle body chemical composition during growth and fattening periods determine animal performance and beef carcass quality. The aim of this study was to estimate the empty body (EB) and carcass chemical composition of growing beef-on-dairy crossbred bulls (Brown Swiss breed as dam with Angus, Limousin or Simmental as sire) using three-dimensional (3D) imaging. The 3D images of the cattle’s external body shape were recorded in vivo on 48 bulls along growth trajectory (75–520 kg BW and 34–306 kg hot carcass weight [HCW]; set 1) and on 70 bulls at target market slaughter weight, including 18 animals from set 1 (average 517 ± 10 kg BW and 289 ± 10 kg HCW; set 2). The linear, circumference, curve, surface and volume measurements on the 3D body shape were determined. Those predictive variables were used in partial least square regressions, together with the effect of the sire breed whenever significant (P < 0.05), with leave-one-out cross-validation to estimate water, lipid, protein, mineral and energy mass or proportions in the EB and carcass. Mass and proportions were determined directly from postmortem grinding and chemical analyses (set 1) or indirectly using the 11th rib dissection method (set 2). In set 1, bulls’ BW and HCW were estimated via 3D imaging, with root mean square error of prediction (RMSEP) of 12 kg and 6 kg, respectively. The EB and carcass chemical component proportions were estimated with RMSEP from 0.2% for EB minerals (observed mean 3.7 ± 0.2%) to 1.8% for EB lipid (11.6 ± 4.2%), close to the RMSEP found for the carcass. In set 2, the RMSEP for estimation via 3D imaging was 9 kg for BW and 6 kg for HCW. The EB energy and protein proportions were estimated, with RMSEP of 0.5 MJ/kg fresh matter (10.1 ± 0.8 MJ/DM) and 0.2% (18.7 ± 0.7%), respectively. Overall, the estimations of chemical component proportions from 3D imaging were slightly less precise for both sets than the mass estimations. The morphological traits from the 3D images appeared to be precise estimators of BW, HCW as well as EB and carcass chemical component masses and proportions.

The potential of pumice as a litter material and its influence on growth performance, carcass parameters, litter quality traits, behavior, and welfare in broiler chickens.

This study evaluated the possibilities of pumice (light stones) as litter material in broiler production. Experimental treatments included wood shavings (WS), acidic pumice (AP), and basic pumice (BP) alone, and in combination; wood shaving + acidic pumice (WSAP) and wood shaving + basic pumice (WSBP) in a ratio of 1:1. Two trials were performed, one in summer, and the other in winter. Each trial involved 750 mixed-sex Ross (308) broilers. Also, there were 15 replicate pens with 50 broilers and a stocking density of 12.5 birds/m2 for each pen at the beginning of each trial. Performance, litter quality, carcass parameters, body and leg abnormalities, body temperature, fear and stress responses, proportional asymmetry, and some behavior expressions were investigated. The litter treatment influenced the final live body weight, litter moisture, ammonia concentration, footpad dermatitis, hock burn, breast blister, hot carcass yield, heart, liver, spleen, abdominal fat, wing and neck ratio, breast and back cleanliness, and the expression of dust bathing and foraging behaviors (P < 0.01; P < 0.05). Furthermore, there was a seasonal effect on live body weight, feed conversion ratio, livability, litter pH, 42-day litter moisture, hot carcass yield, back cleanliness, footpad dermatitis, hock burn, footpad temperature, heterophil-to-lymphocyte ratio, and expression of pecking behavior (P < 0.01; P < 0.05). It is suggested that acidic pumice stone alone or in a mixture with wood shavings could be used as a reliable litter material, alternative to wood shavings.

Effect of dawri-damaa (Pentas schimperiana) leaf meal supplementation on performances, carcass characteristics, and economic feasibility of sheep fed native grass hay.

With a growing export and local market, sheep farming is critical to the economy of smallholder farmers; however, indigenous sheep breeds usually exhibit low carcass output and live weight due to nutritional constraints. The study aimed to investigate the impact of supplementing local sheep with dawri-damaa leaf meal (DDLM) on their performance, carcass characteristics, and profitability when fed native grass hay. The research used a randomized complete block design (RCBD) to administer four feeding treatments (T1, T2, T3, and T4 at 0%, 30%, 50%, and 70% DDLM, respectively) to 20 local uncastrated male lambs having an average 23.72 ± 0.73 kg body weight and average age of 11.72 ± 0.74 months. Greater doses of DDLM in the diet resulted in greater average daily gain (ADG) of 51.4-83.8 g/day and feed conversion efficiency (FCE) of 0.066-0.089 in lambs, compared to 15.0 g/day ADG and 0.025 FCE in lambs under control diet (T1). Additionally, the lambs had increased slaughter body weight (SBW), empty body weight (EBW), and hot carcass weight (HCW) in T4 and T3 compared to other treatments (p < .05). There were no significant differences in dressing percentages (DPs) across any treatment group. The study also discussed the economic viability of supplementing with DDLM, suggesting that feeding 70% daily dry matter of DDLM at 2.5% live weight might be beneficial depending on availability, access, and cost factors. In conclusion, feeding DDLM up to 70% has improved the performance of sheep and is economically feasible. Further research might be required to discover whether such levels of inclusion are harmful and apply different processing methods for feeding animals.

Associations between the rumen microbiota and carcass merit and meat quality in beef cattle

The rumen microbiota is important for energy and nutrient acquisition in cattle, and therefore its composition may also affect carcass merit and meat quality attributes. In this study, we examined the associations between archaeal and bacterial taxa in the rumen microbiota of beef cattle and 12 different attributes, including hot carcass weight (HCW), dressing percentage, ribeye area (REA), intramuscular fat content, marbling score, fat thickness, yield grade, moisture content, purge loss, and shear force. There were significant correlations between the relative abundance of certain archaeal and bacterial genera and these attributes. Notably, Selenomonas spp. were positively correlated with live weight and HCW, while also being negatively correlated with purge loss. Members of the Christensenellaceae R-7, Moryella, and Prevotella genera exhibited positive and significant correlations with various attributes, such as dressing percentage and intramuscular fat content. Ruminococcaceae UCG-001 was negatively correlated with live weight, HCW, and dressing percentage, while Acidaminococcus and Succinivibrionaceae UCG-001 were negatively correlated with intramuscular fat content, moisture content, and marbling score. Overall, our findings suggest that specific changes in the rumen microbiota could be a valuable tool to improve beef carcass merit and meat quality attributes. Additional research is required to better understand the relationship between the rumen microbiota and these attributes, with the potential to develop microbiome-targeted strategies for enhancing beef production.Key points• Certain rumen bacteria were associated with carcass merit and meat quality• Moryella was positively correlated with intramuscular fat in beef carcasses• Acidaminococcus spp. was negatively correlated with marbling and intramuscular fat

Effect of breed and sex on the body weight, slaughter traits, meat quality and meat texture parameters of rabbits

The purpose of the study was to determine the influence of breed on the growth, slaughter traits, quality traits and parameters of texture of meat obtained from Blanc de Termonde and Flemish Giant rabbits. Young animals were weaned on the 35th day of their life. The weight of animals was recorded from birth to the 84th day of life at 7-day intervals. The rabbits were slaughtered between 85th and 90th day of live. Hot carcass weight, chilled carcass weight and giblets weight (liver, lung and heart, kidneys) were recorded. The pH and the colour of the longissimus lumborum and biceps femoris muscles was measured in 45th minute and at 24 hours after slaughter. Shear force and texture parameters were measured. Flemish Giant achieve higher final body weight but lower dressing out percentage than Blanc de Termonde rabbits. Carcasses of Blanc de Termonde characterized with higher loin weight and fat content in carcass. The effect of breed fount to be significant for some components of meat colour like yellowness (b*) in 45th minute and lightness after 24 hours post mortem. The effect of sex found to be significant for acidity of meat and b* component in 45th minute after slaughter and on redness (a*) after 24 hours post mortem. Statistically significant differences between Flemish Giant and Blanc de Termonde rabbits in shear force and texture profile analysis (TPA) were stated. The sex of animals effected only on chewiness parameter for TPA of rabbit meat.

Carcass and non-carcass component yields of trenbolone acetate + estradiol-17β implanted steers vs. non-implanted steers across serial harvest endpoints

ObjectiveWe investigated incremental growth of carcass and non-carcass components and tissue partitioning of implanted or non-implanted steers. Materials and MethodsSteers (n = 80; 271 ± 45 kg) were paired and randomized to harvest date (d 0, 42, 84, 126, 168, 210, 252, 294, 336, or 378), and individuals within pairs were randomized to CON (negative control) or REV (Revalor-XS, Merck Animal Health, on d 0 and 190) treatments. Non-carcass components were removed, cleaned, and weighed. Growth coefficients were calculated using the allometric equation Y = bXa. Results and DiscussionEmpty body weight (EBW), and hot carcass weight (HCW) were 6% greater (P < 0.01) in REV steers versus CON. No treatment effects (P ≥ 0.12) occurred for fill or dressed carcass yield (DY); however, EBW, HCW, and DY increased (P ≤ 0.01) and percentage fill decreased as an effect of days on feed (DOF). Absolute fill weight did not change across DOF (P = 0.82). Implanted steers had greater (P ≤ 0.05) absolute mass of blood, head, hide, oxtail, liver, spleen, bladder, heart, reticulum, omasum, stomach, small intestine, intestines, gastrointestinal tract (GIT), total splanchnic tissue, and total offal. Implanted steers also had smaller (P ≤ 0.05) absolute mass of thymus glands and kidney-pelvic- heart fat (KPH) than non-implanted steers. Non-carcass components with lowest growth coefficients included small intestine (0.02), large intestine (0.12), and brain and spinal cord (0.13). However, KPH (2.01) accumulated at more than 2 times the rate of the empty body, whereas cod fat (1.42) and GIT fat (1.61) grew notably faster than the empty body. Implication and ApplicationsResults suggest that Revalor-XS increased body and carcass weights and altered many non-carcass components and their growth co- efficients, ultimately playing key biological, nutritional, and financial roles across sectors of the beef industry.

Influence of Beef Hot Carcass Weight on Sensory Characteristics of Strip Loin, Eye of Round, and Denver Cut Steaks.

The objective of this research was to investigate the influence of beef hot carcass weight (HCW) on consumer sensory attributes. Beef carcasses (n = 116) were selected based on the USDA quality grade and HCW. Lightweight (LW; 296-341 kg), middleweight (MW; 386-432 kg), or heavyweight (HW; 466-524 kg) carcasses with USDA Choice (LC) or USDA Select (SEL) quality grades were used in this study. Carcasses were tracked through fabrication and the semitendinosus, chuck roll, and strip loin were collected and fabricated into eye of round, Denver cut, and strip loin steaks, respectively, for consumer sensory evaluation. USDA Select MW Denver cut steaks had increased overall liking and texture liking scores and were more tender and juicier than the SEL LW steaks (p ≤ 0.02). USDA Select MW strip loin steaks had increased overall and flavor liking scores and were more tender than the SEL LW steaks (p ≤ 0.02). USDA Choice MW eye of round steaks had increased overall, flavor, and texture liking scores and were juicier than the LW eye of round steaks (p ≤ 0.04). The steaks evaluated in this study were differentially impacted by HCW and little to no clear pattern of effects could be determined across cut or quality grade. Additional research is needed to determine the most acceptable HCW from a consumer perspective.

Effect of supplementing zilpaterol hydrochloride during different periods on energetics, growth performance, carcass traits and fatty acid profile in meat of finishing lambs

To determine the effect of adding β2 agonist zilpaterol hydrochloride during different periods on growth performance, dietary energetic, carcass traits and fatty acid profile, forty male lambs Pelibuey × Katahdin (37.70 ± 0.83 kg) were blocked by body weight and randomly assigned to pens. Treatments consisted in: 1) control, no zilpaterol supplementation, 2) zilpaterol supplementation for 20 d (ZIL20), 3) zilpaterol supplementation for 30 d (ZIL30), and 4) zilpaterol supplementation for 40 d (ZIL40). Compared with control treatment, zilpaterol supplementation increased final live weight (FLW) (3.5 %; P = 0.0563), average daily gain (ADG, 14.8 %; P = 0.0598) and gain:feed ratio (10.3 %; P = 0.0324). As well as hot carcass weight (6.1 %; P = 0.0064), dress out percentage (2.6 %; P = 0.0139) and Longissimus dorsi muscle area (13.7 %; P = 0.0015). Compared to control group, zilpaterol increased (P = 0.0413) observed vs. expected dietary of NEm (net energy requirements for maintenance) and NEg (net energy requirements for growth) (5.7 and 8.1 %, respectively). Twenty days of zilpaterol treatment improved FLW (4.4 %, P = 0.0566) and tended to improve ADG (17.4 %, P = 0.0718) when compared to control group. Only intramuscular fat showed a positive linear effect (P = 0.0006) in stearic fatty acids proportion and negative linear effect (P = 0.0585) in araquidonic fatty acid proportion. We conclude that zilpaterol hydrochloride improved variables of growth performance, energy retention and carcass traits with noticeable effects from 20 d of zilpaterol supplementation.

Performance, carcass characteristics, and meat quality of lambs fed diets containing crude glycerin

The aim of this study was to evaluate the effects of four crude glycerin levels in the diet of feedlot lambs on performance, carcass characteristics, and meat quality. Forty three-month-old crossbred Santa Inês x Dorper lambs weighing 18.2 ± 0.169 kg were used in a completely randomized design, with four diets and 10 replicates per diet. The animals were housed in individual pens. The trial period (42 days) was preceded by 14 days of adaptation to handling and diet. Final body weight (FBW), empty body weight (EBW), average daily weight gain, feed conversion, and feed efficiency did not differ with crude glycerin levels in the diet. Nutrient intake (dry matter (DM), ether extract (EE), crude protein (CP), and neutral detergent fiber (NDF)) did not differ depending on crude glycerin levels. In the evaluation of carcass characteristics, there was a quadratic effect due to crude glycerin levels on hot carcass yield (maximum point- maxP = 9.73%), leg perimeter (maxP = 9.45%), fat thickness (maxP = 7.41%), and leg weight (maxP = 8.69%). Loin weight and conformation showed a linear increase as a function of crude glycerin levels. The other studied variables were not affected by crude glycerin levels in the diet. In the non-carcass components, the full gastrointestinal tract, mesenteric fat, omental, and perirenal fat were not influenced by crude glycerin levels. Regarding meat quality, no effects were observed on the parameters evaluated in the longissimus dorsi. The addition of up to 15% crude glycerin in the lamb's diet does not affect its performance, however, the addition of up to 8% improves carcass characteristics and maintains meat quality.

Novel 4th-generation phytase improves broiler growth performance and reduces woody breast severity through modulation of muscle glucose uptake and metabolism.

The objective of the present study was to determine the effect of a novel (4th generation) phytase supplementation as well as its mode of action on growth, meat quality, and incidence of muscle myopathies. One-day old male broilers (n = 720) were weighed and randomly allocated to 30 floor pens (24 birds/pen) with 10 replicate pens per treatment. Three diets were fed from hatch to 56- days-old: a 3-phase corn-soy based diet as a positive control (PC); a negative control (NC) formulated to be isocaloric and isonitrogenous to the PC and with a reduction in Ca and available P, respectively; and the NC supplemented with 2,000 phytase units per kg of diet (NC + P). At the conclusion of the experiment, birds fed with NC + P diet were significantly heavier and had 2.1- and 4.2-points better feed conversion ratio (FCR) compared to birds offered NC and PC diets, respectively. Processing data showed that phytase supplementation increased live weight, hot carcass without giblets, wings, tender, and skin-on drum and thigh compared to both NC and PC diets. Macroscopic scoring showed that birds fed the NC + P diet had lower woody breast (WB) severity compared to those fed the PC and NC diets, however there was no effect on white striping (WS) incidence and meat quality parameters (pH, drip loss, meat color). To delineate its mode of action, iSTAT showed that blood glucose concentrations were significantly lower in birds fed NC + P diet compared to those offered PC and NC diets, suggesting a better glucose uptake. In support, molecular analyses demonstrated that the breast muscle expression (mRNA and protein) of glucose transporter 1 (GLUT1) and glucokinase (GK) was significantly upregulated in birds fed NC + P diet compared to those fed the NC and PC diets. The expression of mitochondrial ATP synthase F0 subunit 8 (MT-ATP8) was significantly upregulated in NC + P compared to other groups, indicating intracellular ATP abundance for anabolic pathways. This was confirmed by the reduced level of phosphorylated-AMP-activated protein kinase (AMPKα1/2) at Thr172 site, upregulation of glycogen synthase (GYS1) gene and activation of mechanistic target of rapamycin and ribosomal protein S6 kinase (mTOR-P70S6K) pathway. In conclusion, this is the first report showing that in-feed supplementation of the novel phytase improves growth performance and reduces WB severity in broilers potentially through enhancement of glucose uptake, glycolysis, and intracellular ATP production, which used for muscle glycogenesis and protein synthesis.

Meta-analysis of organic chromium dietary supplementation on growth performance, carcass traits, and serum metabolites of lambs

There are inconsistent results on the effects of organic chromium (OCr) dietary supplementation on productivity, carcass traits, and blood metabolites of sheep. Therefore, this study aimed to evaluate the effects of OCr dietary supplementation on growth performance, carcass traits, meat composition, and serum metabolites of lambs using a meta-analytical approach. The final database included 16 studies from which the variables of interest were obtained. Data were analyzed using a random effects model, and results are presented as weighted mean differences (WMD) between OCr-supplemented and non-OCr treatments. OCr dietary supplementation did not affect dry matter intake; however, average daily gain increased, and feed conversion ratio decreased in response to OCr dietary supplementation. Dietary supplementation with OCr increased hot carcass weight, hot carcass yield, cold carcass weight, and Longissimus dorsi muscle area but decreased backfat thickness. In meat, OCr supplementation increased Warner-Bratzler shear force and protein content and decreased intramuscular fat content. In the blood, OCr dietary supplementation increased the serum concentration of insulin and triiodothyronine. However, serum concentrations of glucose, cholesterol, triglycerides, and thyroxine decreased in response to OCr dietary supplementation. In conclusion, organic chromium can be used as a dietary additive to improve average daily gain and feed conversion ratio in lambs and, at the same time, improve carcass traits, meat chemical composition, and serum metabolites.

Influence of Finishing Systems on Carcass Characteristics, Composition, and Fatty Acid Profile of Bison Bulls

The objective of this study was to determine the influence of grain- and grass-finishing systems on carcass characteristics of bison bulls and proximate and fatty acid compositions of bison steaks. Bison bulls grazed native pasture until approximately 25 mo of age, then were randomly assigned to grain-finishing (n=98) or grass-finishing (n=98) treatments. Bulls were slaughtered at approximately 30 mo of age. Hot carcass weight (HCW), ribeye area, backfat thickness, kidney fat percentage, marbling score, and instrumental color (L*,a*, and b*) of the ribeye and subcutaneous fat were recorded. Skeletal maturity, lean maturity, and fat color were subjectively scored. Strip loins were collected from a sub-sample of carcasses, fabricated into 2.5-cm steaks, and designated for proximate, cholesterol, or fatty acid analyses. Grain-finished bulls had greater (P&amp;lt;0.0001) HCW, dressing percentage, ribeye area, backfat thickness, kidney fat percentage,and marbling score. The a* and b* values of the ribeye and a* value of subcutaneous fat were greater (P&amp;lt;0.0001), but the L* and b* values of subcutaneous fat were less (P&amp;lt;0.0001) for grain-finished bulls. A greater proportion (P&amp;lt;0.001) of grain-finished carcasses had moderately bright red lean color, whereas a greater proportion (P&amp;lt;0.0001) of grass-finished carcasses had moderately yellow fat color. Steaks from grain-finished bulls had an increased percentage of crude protein (P&amp;lt;0.0001), fat (P&amp;lt;0.0001), and ash (P=0.0006) content but less moisture (P&amp;lt;0.0001). Steaks from grain-finished bulls had more (P&amp;lt;0.001) cholesterol and palmitic, stearic, oleic, linoleic, and arachidonic acids in addition to more total fatty acids (mg/g of wet tissue). However, for total fatty acids, grass-finished steaks had a greater (P&amp;lt;0.0001) percentage of polyunsaturated fatty acids. These data indicate that the finishing system influences the composition of bison bull carcasses as well as the nutrient profile of bison meat.

Carcass characteristics and meat quality of cull cows from different genetic groups

We aimed to evaluate the quality of the carcass and meat of cull cows from different genetic groups. It was considered 48 cows being 16 of the Nellore breed (NEL), 16 ½Angus ½Nellore (ANGNEL), and 16 ½Caracu ½Nellore (CARNEL), slaughtered at the end of eight pregnancy seasons, with approximately 11 years of age. For carcass analysis, body weight at slaughter (SW), hot carcass weight (HCW), carcass yield (CY), carcass finishing (CF), fat distribution (FDIST), cold storage conformation (CSC), marbling (MAR), subcutaneous fat thickness (SFT), ribeye area (REA), internal depth (INTD), external depth (EXTD), carcass length (CL), physiological maturity (FMAT), muscle color (COLOR) and texture (TEXT). For meat analysis, samples taken from the Longissimus muscle were analyzed after zero and 14 days of maturation for exudation losses (ExuL at 0 and 14 days), cooking losses (CookL), pH (pH at 0 and 14 days), color components of meat (L*, a* and b* 0 and 14 days) and shear force (SF at 0 and 14 days), the ether extract (EE) of the samples was also evaluated according to the genetic group of the cull cows. The Means were compared according to the adjusted Tukey-Kramer test (α = 0.05). The data were evaluated for the presence of outliers, homogeneity of variance, and normality of residuals. The effects of genetic groups on the described characteristics were evaluated by restricted maximum likelihood (REML) analysis, adjusting a mixed model containing the effects of cow age, genetic group, and slaughter date. NEL and ANGNEL cows presented higher SFT results when compared to CARNEL cows. The REA, INTD, and EXTD, ANGNEL and CARNEL cows obtained greater results when compared to NEL cows group. There was no significant effect on the genetic group of cull cows for the variables CY, CF, FDIST, CSC, MARM, FMAT, COLOR and TEXT. A significant difference was observed only for the L* characteristic (0 and 14 days of maturation), in which NEL cows presented darker meat than ANGNEL, with CARNEL cows having intermediate results. The ANGNEL cull cows have higher slaughter weights, and carcass weights, and AOL and EGS with better carcass finish. Cull cows slaughtered at an advanced age, between 10 and 11 years old, have similar meat quality. We recommend the meat maturation process for 14 days to improve the tenderness of the meat from cull cows, since in this 14-day meat maturation process, calpains degrade the myofibrillar proteins at certain internal points of the molecules and improve the tenderness of the meat, regardless of the genetic group.

97 Use of genomic testing for predicting performance of finishing steers

Abstract Genomic testing is a commercially available tool that has the potential to be beneficial in selecting cattle for retained ownership, as well as making management and marketing decisions after finishing. The objectives of this study were to determine if commercially available genomic tests are predictive of differences in finishing performance of steers from sires selected based on divergent growth and milk EPDs. The commercial genomic testing of milk and average daily gain (ADG) scores used in the current experiment were based on Neogen Igenity Beef test results. Two trials were conducted at the OSU Willard Sparks Beef Research Center in Stillwater, Oklahoma. These experiments used two sets of steers from the OSU Range Cow Research Center (400 ± 13 kg, n = 154) from a spring calving cowherd (South Range Unit) and a fall calving cowherd (North Range Unit) of primarily Angus ancestry. Following preconditioning and a wheat pasture stocker program (South Range) or dry lot growing period (North Range), steers were allocated into pens (n = 5 animals/pen) by Igenity ADG Score: low growth (LG) had scores ranging from 1 to 4, medium growth (MG) had scores from 5 to 6, and high (HG) had scores from 7 to 10. Steers were blocked by initial BW and fed a step-up diet for 30 d before being switched to a finishing ration diet (8% prairie hay, 20% Sweet Bran, 62% dry-rolled corn, 5% liquid supplement, and 5% dry supplement [DM basis]). Cattle were fed ractopamine hydrochloride for 30 d before slaughter. The heavy block was on feed for an average of 136 d, while the light block was on feed for an average of 160 d. Data were analyzed as a randomized complete block design using the mixed procedure of SAS (SAS Inst. Inc., Cary NC) with pen as the experimental unit and finishing pen within block as the random statement. During the feeding period, HG steers gained more rapidly than MG or LG steers, with ADG of 2.08, 1.94, and 1.90 kg/d, respectively (P = 0.04). Because gains were greater, BW at slaughter for the HG steers was greater than MG and LG, averaging 690, 669, and 660 kg, respectively (P = 0.04) and hot carcass weights were greater for HG than MG and LG, averaging 438, 426 and 418 kg, respectively (P = 0.02). There were no other differences (P &amp;gt; 0.19) in carcass characteristics among steers. These data suggests that the genomic testing is accurate predictor of performance and can be used by producers can make better marketing decisions in selecting cattle for the retained. Genomic testing could be very beneficial for producers looking to minimize risk and maximize performance in their herd.

126 Effects of Tall Fescue Seeds and Quercetin on the Meat Quality of Finishing Lambs

Abstract Tall fescue is a major cool-season grass for grazing livestock in North America. However, it is typically infected with endophyte fungus, and the intake of the infected tall fescue was toxic to ruminant animals. Quercetin is one of the natural flavonoids that could increase the anti-inflammatory and antioxidant capacity of an animal. This experiment aims to investigate the effects of infected tall fescue seeds on the carcass characteristics and meat quality of finishing lambs, and also to determine the mitigation effect of quercetin on the toxicity of tall fescue seeds. A total number of 24 lambs were randomly assigned to four groups: 1) Control group (C, n = 6), tall fescue seed group (E+Q-, n = 6, feed with tall fescue seed infected with alkaloid endophyte), tall fescue seed, and quercetin group (E+Q+, n = 6, feed with tall fescue seed infected with alkaloid endophyte), and quercetin group (E-Q+, n = 6, feed with quercetin). All the groups were fed ad libitum for 42 d. The longissimus dorsi muscle of each lamb was collected to analyze the meat quality parameters. The results show that the tall fescue seed decreased the final body weight and the hot carcass weight of finishing lambs (P &amp;lt; 0.05). Intake of tall fescue seed with quercetin increased the meat color parameters (L*, a*, b*, C, and h) significantly (P &amp;lt; 0.05). The tall fescue decreased the intramuscular fat content in the longissimus dorsi muscle and also modulated the fatty acids composition (P &amp;lt; 0.05). In conclusion, infected tall fescue negatively affected the carcass characteristics and intramuscular fat deposition of finishing lambs. However, the quercetin didn’t mitigate the influence of tall fescue seeds on carcass characteristics but increased the meat color characteristics.

Effect of Feeding Level on Growth and Slaughter Performance, and Allometric Growth of Tissues and Organs in Female Growing Saanen Dairy Goats.

This study aimed to investigate the effect of feeding level on the growth and slaughter performance, and allometric growth of tissues and organs in female growing dairy goats. The trial included 10-20 and 20-30 kg weight stages with 48 female goat kids. The 24 goat kids in each stage were divided into 8 blocks based on weight, with 3 kids per block. Then, three kids from each block were randomly assigned to one of the three treatments, namely ad libitum (AL100), 70% of ad libitum (AL70), or 40% of ad libitum (AL40). The slaughter trial was conducted when the AL100 kids reached the target weight of 20 or 30 kg. The results showed that the ADG and feed conversion rate showed a linear decline as the feed level decreased (p < 0.05). Compared with the AL70 and AL100 groups, the AL40 group exhibited lower shrunk body weight, empty body weight, hot carcass weight, net meat rate, carcass meat rate, and visceral fat weight (p < 0.05) in both stages. Moreover, the AL40 group showed lower weights for skin and mohair, blood, rumen, small intestine, large intestine, mammary gland, and uterus than the AL70 and AL100 groups (p < 0.05) in both stages. However, feeding level did not affect organ indices in the two stages (p > 0.05). The bone, skin and mohair were isometric (b ≈ 1), but the muscle, visceral fat, and most internal organs were positive (b > 1) in both stages. In conclusion, feeding level affects the growth and development of dairy goats, which vary depending on the body weight stage and specific tissues and organs.